Stephen M. Rosenthal, MD, is cofounder and medical director of the multidisciplinary UCSF Child and Adolescent Gender Center (CAGC), where he cares for young transgender clients. He also cares for pediatric clients with endocrine disorders, such as abnormalities involving thyroid function or growth and puberty. Dr. Rosenthal is one of four principal investigators for the Impact of Early Medical Treatment in Transgender Youth, a multicenter study sponsored by the National Institutes of Health and the Eunice Kennedy Shriver National Institute of Child Health and Human Development. He is currently a member of the board of directors of the World Professional Association for Transgender Health.